Process for determining moisture in aggregate



R. E. ROBB March 4, l 930.

PROCESS FOR DETERMINING MOISTURE IN AGGREGATE Filed Aug. 17, 1928 1N VENTOR.

Foals-R7 5. F055,

A TTORNEY5.

Patented Mar. 4,1930

UNITED STATES PATENT ori ce ROBERT E. ROBB, OF EVANSVILLE, INDIANA IPROCESS FOR DETERMINING MO ISTURE IN AGGREGATE Application filed August17,

The object of this invention is the determination of the moisture inaggregate or any other non-soluble, granular material bein' tested. Theprocess depends upon the weig tor relative specific gravity of the ma toreadily and accurately predetermine the amount of moisture contained inthe gravel,

stone, sand or other aggregate or other nonsoluble, grannular materialwhich is to be used for concrete construction, and to do this Withoutthe necessity of drying a sample of the material and Without havin toresort to the'use of computations, charts, gures, tables or othermechanical aid. This enables such mechanic or other person without anyspecial education, training or skill to scientifically and accuratelymake concrete of the desired quality. g

The process briefly stated consists first in preparing a test standardand then applying the test standard in determining the amount ofmoisture in the aggregate. This test standard may be repeatedly employedin carrying out the portion of the process directly relating to thedetermination of the moisture in the actual material to be tested orused. H The process of determining the test standard consists in,introducing a known weight of dry aggregate into a constant volumeofWater or other liquid, determining the amount of water displaced by thesaid aggregate and then determining the weight of the remaining waterand dry aggregate. The process of applying the test standard indetermining the moisture in the moist aggregate to be tested consists inplacing the same weight of aggregate to be tested, excludingt hemoisture therein, in water of constant volume as used in the standardtest and finally 1928. Serial No. 300,235.

determining the difference between the water displaced in thestandard'test and the water.

displaced by the moist aggregate, which gives the water actually carriedby the sample of moist aggregate tested and which may be measured in anyconvenient units or percentage. This latter process may be specificallycarried out'by introducing the moist aggregate to be tested into thesame volume of water used in the standard test until their combined netWeight equals or counterbalances the weight in the standard test and bydetermining the percentage ofdifi'erencein the amount of water displacedby the moist aggregate and that displaced in making .the

standard test. v

The full nature of the invention willibe understood from theaccompanying drawings and the following description and claims:

In the drawings Fig. l is a central vertical section through the mainvessel with a certain or constant volume of water therein. Fig.

2 is a side elevation of a counterpoise and scale beam having the saidmain vessel silspended therefrom shown in central vertical section andcontaining a known weight of aggregate and a central vertical sectionthrough a smaller vessel for containing displaced waterwith a tubularconnection from said main vessel discharging into said displacementwater vessel. Fig. 3 is a transverse section through the*counterpoise onthe line 3-3 of Fig. 2. Fig. 4 is a central vertical section of thedisplaced water vessel with the measuring bar in elevation installed insaid vessel, showing its position at the end of the standard test. Fig.5 is the same with the measuring bar in its position at the end of thetest of the moist aggregate to be tested; Fig. 6 is a centrallongitudinal section of the apparatus assembled for transportation.

While water is referred to herein as the liquid used, the invention isnot limited to any particular liquid as some other kind of out theprocessor processsconstituting this invention. But, to illustrate thegeneral nature ofthe invention, there is one very simple, cheap andeasily carried and operated apparatus which is shown herein.

There are two groups of process steps employed repeatedly fordeterminingthe:

moisture in the actual aggregate to be tested in any number of instancesso long as the aggregate to be testedis of the same charactersubstantially as the aggregate. used in making the standard test. Thusthe; same standard test may be used in carrying out the remainder of thetotal process in making 40 tests of actual aggregate or used for manydays in the same kind of work. 'This renders it unnecessary to make astandard test more than one time for determining the moisture in theaggregate to be-tested of the same general nature.

Furthermore, the same apparatus may be used in making each of these twokinds of 7 ,tests, the standard test and the final test and this is oneof the great this process.

The following are the steps and the apparatus usedin making the standardtest ume or weight of water isconstant.

location of pet cook 11 in vessel 10 may be impericallyor arbitrarilydetermined, al- 'though,.in practice, the volume of. water for measuringmoisture in aggregate:

In the first place, a known or constant .volume of water or other liquidis introduced should be enough to cover a certain weight of dryaggregate or other material to be used in this part of the process,sayfive pounds. Therefore, the position of the pet cook 11 would be variedaccording to the character of the material to be tested. It requiresmuch less water to coverfive pounds of sand than to cover five pounds ofcrushed rock, because the crushed rock has larger spaces between theparticles. Hence, the particular location of the pet cock 11 is chieflydependentupon the character of the material to betested. The water isintroduced into vessel 10 and, when it ceases to flow out of said petcock 11, it is closed, as shown in Fig. 2.

In carrying out the invention, broadly speaking, the next step is tointroduce into said vessel 10 a known or predetermined advantages ofweight of dry aggregateof the kind that is to be tested. In the usualsize of the apparatus herein discdosed, five pounds of such dryaggregate is placed in vessel 10, as seen in Fig. 2. The pet cook 11 hasbeen closed and another pet cock 17 is opened, as shown in Fig. 2, forthe displacement water or overflow from vessel 10 to pass'into thedisplacement vessel 18, shown in Fig. 2, which rests on the floor ortable 1 9 and has a dishshape'd bottom cap 20, as herein shown.

The water displaced from vessel 10 by the dry aggregate introducedtherein passes through the open pet cock 17 through a rubber tube21 intheapparatus herein shown. 1,

Theapparatus which may be used for ac- I 'complishing this second stepin the process may diifer in many respects from that herein shown. Thelocation of pet cock 17 in vessel 10 of the apparatus herein shown isusuall determined imperically. It must be locate above the water and,say five pounds of, the dry aggregate introduced in the yessel 10, andbelow thetop of the water in said vessel after the dry aggregate hasbeen placed therein. It could, therefore, be located higher if crushedrock or coarse material constitutes the aggregate than if fine materialwere-used, which holds less water. It is practically immaterial wherethe pet cock 17 .is. located between the above-mentioned limits, but.-itmust be above the aggregate and below the top of the water after theaggregate is placed in the vessel.

The ultimate result of the total process or test will be the samewherever the pet cock 17 may be, if located between said limits. Afterthe known amount of dry aggregate has been placed in said vessel 10 andthe displaced water has gone over into vessel 18 through pet cock17, thevessel 10 findits contents are weighed by, any suitable weighing meansand, when the weight or volume of the displaced wateris determined, thesecond step of theprocess is completed. Y

However, the Weighing means in the apparatus herein shown is preferableover any other weighing means, as it is merely a I counterbalancingmeans which really requires short end of the balancing beam or scalebeam 12, which has knife-edge bearings'13 in a saddle strap'113suspended by a'hanger 14 to any fixed support, and a counterpoise 15slidable on said beam. Then the dry aggregate is introduced into thevessel 10, as shown in Fig. 2. In the apparatus herein shown, as usuallymade, five pounds of such the balancing beam 12 so as to substantiallydry aggregate is placed in said vessel and the counterpoise 15 is slidtoward the end of counterbalancethe vessel 10 with its contents of waterand aggregate. After the surplus or displaced water has run out throughpet cock 17 into the displaced water vessel 18, the counterpoise is thenmoved to an exact balancing position, as indicated by dotted lines inFig. 2. Obviously, the dry aggregate could be introduced into vessel 10before it is suspended on the balancing beam 12, ,but the practice hasgenerally been as above explained. Anair bubble means 16 is located inthe beam 12, as shown near the right-hand end of the beam, to indicatewhen there is an exact counterbalance between the vessel 10 and itscontents on the one hand and the scale beam and counter-poise on theother hand; f

I The position of the poise 15 which-counter balances vessel 10 and itscontents may be determined by weight graduations-on the weigh- .ingscale beambut which are not here shown balancing position by suitablemeans, and, in

the subsequent steps of the process, and particularly those devoted tothe test of the moist aggregate, this result of the standard testeanberepeatedly used as long as the moist aggregate, as herein explained,is of the same character as the dry aggregateused in making the standardtest The" dry aggregate used in the standard test, therefore, must be ofthesame character as the moist aggregate Y with which one is expected towork and utilize the standard test. Thus, ifthe work relates to testingmoist sand or fine material, it must be that kind of dry material asused in making this standard test. If it be coarse moist material, orcrushed rock, to be used in making the standard test, the same kind ofdry ma- .terial must be used in making the standard test.

The weight of vessel 10 andthe contents having been weighed, orcounterbalanced which is the same thing, as above explained,

a memorandum is kept of the weight, or,

if using the apparatus herein set forth, counter oise 15 is secured tothe beam in its counter alancing position. That maybe done by. any meansbutherein there is shown in Fig. 3 a cross-section of the counterpoiseThis is preferably. a headed screw which is tightened in place on thebeam 12. The poise 15 is provided with a longitudinal slot 37 into whichthe head of the stop projects and also a recess 137 is located in theinner wall of the poise leading from the slot 37, which recess is largeenough to receive the head of the stop 35 and when the counterpoise 15is located at the balancing position, it is turned so that the head ofthe stop 35 ,will project into the recess 37 and hold the poise 15 inthe balancing position for the various subsequent tests and uses of theapparatus in making tests of moist aggregate of thesame kind for whichthe standard test hasbeen made. This will enable the parts of theapparatus to be separated and handled without the poise 15 changingposition on the beam 12, so that it can be used in dozens ofoperations,and this is one of the results of the standard test herein referred to,as the position of the poise establishing this test will remain the samewhile testing moist aggregate of this kind.

On the opposite side of the beam is a similar stop and slot for adifierent grade of aggregate and the poise there has an internal groove38.

The next step in the operation is to measure the displaced water invessel 18 while making said standard test with the dry aggregate. Thiswater may be measured as desired. It may be weighed by any suitablemeans or it may be measured, in a sense, by the measuring bar 25 shownin Fig. 4. The measuring or weighing of the displaced water, however,may be made before the poise 15 is secured on the beam 12 or afterwards,

asdesired. The measuring bar 25 consists .of a metal bar with one ormore scale strips 27 and 28 on it. Scale strip 27 is for relatively finematerial and scalestrip 28 is for relativelycoarse material. These scalestrips are provided with graduations, as shown, indicating thepercentage of moisture in the moist aggregate being tested or to be,tested in terms with reference to the weight of the dry aggregateemployed in making the standard test. That is, if there is one pound ofwater to ten pounds of aggregate, there would be ten percent of moistureand that would be indicated by the numeral 10on the scale. This is ametal bar having secured to its lower end a piston-like head or bottom23 which is insertable into vessel 18 down to the water.

Scale bar 25 is provided with longitudinal slots 29 and the scale strips27 and 28 are held thereon by screws 30 extending through said, slots,whereby said scale strips are longitudinally adjusted according towhether the material is fine or coarse. These scale strips are locatedin their proper places on the bar 25 by adjusting them so that when thepiston-like member 23 rests upon the top of the displaced water invessel 18, the zero mark on the scale strip will register with thetop'of vessel 18. Scale strip 28 is adjusted in a similar manner withreference to coarse material.

The foregoing steps in the process are em- 'ployed in making what iscalled the standard test, andfin the apparatus herein shown, in Fig. 5,results of such-tests are the adjust- "ment of the proper scale strips27 and 28 on the .measuring bar 25 for indicating the displacement ofwater by the aggregate tested, and the counterbalancing position of thecounterpoise 15 on the beam ,12. If such j apparatus is not used, theweight in pounds and ounces of the vessels and 18 and their contents, asshown in Fig. 2, are recorded and the percentageof moisture in theaggregate determined therefrom.

If it be desired that the amount of water actually contained in onecubic foot of the material be measured volumetrieally, scale strips 127and 128 are secured on the back side of the measuring bar 25 withgraduations 131 thereon which indicate the gallons or pounds of waterper cubic foot in similar aggregate in damp, loose condition, asshown'in Fig. 5. I

After the standard test has been made, as heretofore explained, 1 thesecond stage or phase of the process consists in testing moist aggregateof'the kind that is to be used in the concrete or other work and inusing the results of the standardtest in carrying out this last part ofthe process. Ifa simple so weighing apparatusindicating pounds andounces be employed, the next step in the process consists in introducingan equal weight of moist aggregate of the kind of aggregate used in thestandard test with the same amount of water, and. then separating the.member rests on the water therein, and the nu- .down in the side ofbeam 12. Then the vessel being tested is introduced into the vessel 10until the vessel, and its contents counterbalance the counterpoise 15inits line location as shown in Fig. 2, after the surplus water hasceased flowin through pet cock 17 into vessel 18. The disphiced waterwhich is then in vessel 18 is deemed to water. 1

The water now contained in vessel 18 ismeasured' by the measuring device25\being inserted into said vessel until the piston-like so meralexposed at the upper end of the vessel will indicate the percentage ofmoisture contained in the aggregate last'introduced into the vessel 10*,which was the sample'of moist aggregate. In other words, with this test,85 if the aggregate weighed five pounds and the water displaced wasthree-fifths pound, the scale would indicate six percent of moisture inthe aggregate tested.

The apparatus shown herein is. assembled as appears in Fig. 6 so that itis easily trans-' ported. As there seen, the vessel 10 becomes anexternal holder of the remainder of the apparatus with the loop 110 as ahandle for carrying it. ,The measuring bar 25 is first placed in vessel18 with the piston-like end. 26 at the bottom. Then the scale beam 12 isplaced in the vessel 10 with the counterpoise 15 at the bottom and thehanger. 14 hanging surplus or displaced water, until the balance :18 iinverted and inserted in the 'vessel. 10-

weighs the same asin the standard test, then weighing said displacedwater, and deducting the weight of the displaced water in the standardtest from the weight of thedisplaced water in the moist aggregate test,which difierence will be the amount of water actually carried by thesample of the moist aggregate .tested, or the difference in the watershown in Figs. 4 and 5.

This latter amount may be measured in any convenient units or expressedby determining the percentage of this latter amount, that is,

' of thewater actually carried by the moist agrgate in proportion to theweight of the ry aggregate in the standardtest. I But preferably thesecond part of the total process is carried out by the use of the samemeans substantially as is employed as shown herein for making thestandard test. This avoids the preservation of any records or tables ormaking any computations.

The next step employedyif one uses the apparatus shown herein, is toempty the vessels In fact, the apparatus is carried around from place toplace for use in connection with determining the moisture in theaggregate to be tested at any time or place. In making the iiifioistaggregate test, the vessel 10 is filled 10 and 18.used in making thestandard test.

with the bottom cap 20 covering or constituting a lid for the upper endof the vessel 10. The'assembled apparatus weighs only a few pounds andis easily carried by one hand and quickly set up and used in makingeither the standard test or the final moist aggregate test.

1 The invention claimed is: 1. The process of determining the moisturein aggregate,which,process consists first in preparing a test standardby determining the amount of liquid displaced by a known weight of dryaggregate of the kind-of aggregate to be tested-when placed in liquid ofknown volume,'then determining the amount of liquid displaced by themoist ag egate to be tested P by placing the same weig t of aggregate inthesame volume of liquid as used in the standard test, and finallydetermining the difference between theamount-of liquid displaced in thestandard test and theamount of liquid displaced in the test of the moistaggregate.

2. The process of determining the m isture in aggregate,-which processconsists rst in amount of liquid displaced by a known weight of dryaggregate of the kind to be tested when placed infliquid of knownvolume, then determining the amount of water displaced by the moistaggregate to be tested when .the

be the quantity of displaced 75 preparing a test standard by determiningthe 3.

. the liquid same weight of aggregate irrespective of the moisturecontained therein is placed in liquid of constant volume as used in thestandard test, and finally determining the liquid displaced in thestandard test as compared with displaced by the moist aggregate. thedifference being the amount of liquid actually carried by the sample ofmoist aggregate tested.

3. The process of determining the moisture inaggrega'te by firstintroducing a known weight of dry aggregate in a known volume of liquid,determining the amount of liquid displaced by said aggregate,determining the weight of said aggregate and the remaining liquid in thestandard test, then introducing the moist aggregate to be tested intothe same volume of liquid until their combined weight after the liquiddisplacement equals the I in aggregate by introducing a of liquid'andall weight of the test standard, determining the amount of liquiddisplaced by the moist aggregate therein, and finally determining thedifierence in the amount of liquid displaced by the moist aggregate incomparison with the amount displaced in making the test standard.

4;. The process of determinin the moisture known weight of dry aggregatein a known volume of liquid, determining the amount of liquid displacedby said aggregate, 'counterbalancing the weight of said aggregate andremaining liquid by a weight as a test standard, then introducing themoist aggregate to be tested in the same volume of liquid until theyafter the liquid displacement counterbalance the weight in said standardtest, determining the amount of water displaced by the moist aggregate,ference in the amount of water displaced by the moist aggre ate ascompared with that displaced in maiin the test standard.

5. The process of termining the moisture in aglgre ate by firstintroducing a known weig t 0 dry aggregate in a known volume owing aportion of said liquid to be displaced, weighin the remaining liquid andaggregate, weig ing the displaced liquid, then introducing moistaggregate to be tested into the liquid until the weight of aggregate inliquid shall be the same as the weight of the dry aggregate and liquid,weighing the liquid displaced by the moist aggregate, and determiningthe difierence between the amount of liquid displaced by the dryaggregate and .the moist aggregate, which dilference will inand finallydetermining the dif-,

known volume of c said vessel by suitable means, introducing moistaggregate to be tested in such vessel with said known volume of water,removing the surplus. water until the remaining water and moistaggregate shall be counterbalanced by the same means, and determiningthe difference in the amount of water displaced by the moist aggregatein comparison with that displaced by the dry aggregate.

7. The process of determining the moisture content of aggregate whichcomprises introducing a measured quantity of aggregate into a measuredquantity of liquid to establish a standard indication, then introducinga corresponding quantity of moist aggregate to be tested into suchmeasured quantity of liquid, and' determining the displacement of saidliquid with relation to the standard indication.

In witness whereof, I have hereunto aflixed m si ature.

. y gn ROBERT E. ROBB'.

